In order to observe the inside of a subject, such as the inside of a machine structure, in industrial fields, and such as the inside of a patient's body, in medical fields, an endoscope apparatus has conventionally been widely used. Such an endoscope apparatus includes an elongate insertion part having a bending portion capable of being freely bent and a hard distal end on the distal side, and being inserted into a subject, and an observation portion is provided at the tip of the insertion part. Also, the insertion part is inserted into the subject, the bending portion is bent by an operating part on the proximal side, and the orientation of a tip is adjusted, so that a desired observation position can be observed inside the subject by the observation portion at the tip. Meanwhile, the inside of the subject observed by the endoscope apparatus mostly does not have enough brightness to be observed by the observation portion. For this reason, an illumination device for illuminating the inside of the subject is built into the endoscope apparatus.
As such an illumination device, an illumination device including following three constituent elements is proposed (for example, refer to Japanese Unexamined Patent Application, First Publication No. 2006-296656 and Japanese Unexamined Patent Application, First Publication No. 2006-288535). That is, the illumination device includes a light source section provided on the proximal side of an insertion part to output laser light as excitation light, a light guide disposed from a proximal end of the insertion part to the tip to guide the laser light emitted from a light source, and a fluorescent member provided at the tip of the insertion part to emit the laser light guided by the light guide as the excitation light.